Heat exchanger



Patented June 16, 1925.

UNITED STATES EDWIN R. COX, 0F LOS ANGELES, CALIFORNIA.

HEAT EXCHANGER.

Application med october 31, 1921. serial No. 511,eo2.

T0 all whom t may concer/n.'

Be it known that I, EDWIN R. Cox, a citizen of the United States, residing at Los Angeles, in the county of Los Angeles and State of California, have invented a new and useful Heat Exchanger, of which the following is a specification.

This invention relates to heat exchangers and is particularly directed to a device in which a transfer of heat from one gas or fluid to another gas or fluid is effected by conduction.

Devices of this general character provide for a circulation of one gas or fluid through tubes and for a circulation of another gas or fluid around the tubes, the cooler gas or fluid absorbing the heat from the hotter gas or fluid during the passage of the two through the device.

In designing such a heat exchanger a maximum area of heat conducting surface must be provided, and particularly where the conductance of one gas or uid is much higher than that of the other, it is of advantage to greatly increase the surface area in contact with the gas 'or fluid of lower conductivity without proportionately increasing the surface area in contact with the gas or fluid of higher conductivity.

It is therefore an object of the present invention to provide a heatexchanger having such increased surface area for contact by one of the gases or fluids entrained therethrough.

Another object is to provide a heat exchanger of high efficiency and of durable and cheap construction.

Another object is to provide a heat exchanger in which a plurality of tubes extend through each of a series of transverse ns which are so formed and assembled as to firmly grip the walls of the tubes to form a perfect heat-conducting contact between the tubes and fins.

A further object is to rovide a method of constructing a heat exc anger of `the above character.

' -Various other objects and advant es will be more fully apparent from the fo owing description of the accompanying drawings which form a part of this disc osure, and which illustrate a preferred form of embodiment of the invention.

0f the drawings:

' 1 is a vertical section I through my improved'heat exchanger. i y

Fig. 2 is a transverse section on line 2-2 of Fig. 1. Fig. 3 is an enlarged detail section showng the connection between the tube and the Fig. 4 is a section showing the nesting together of the lips of the fins before the fins are compressed.

In the drawings I have illustrated one form of heat exchanger comprising a chamber 1 having an inlet 2 and an outlet 3, the side walls 4 of the chamber being formed of two sections secured together by bolts 5, (see Fig. 2) and the end walls 6 being separate plates bored to receive the opposite ends of a series of transverse tubes 7. Engaging the outer surface of one end plate 6 is a manifold plate 8 providing an inlet 8 and engaging the opposite end plate 6 is a manifold plate 9 providing an outlet 9*, each manifold plate having chambers 10 serving to conduct the as or fluid through the several tubes inl a zig-zag path, as indicated by the arrows in Fig. 1. The manifold plates and the end plates are secured to the side wall members by bolts 11 to form a rigid unit.

A plurality of relatively spaced sheet metal plates or fins 12 are positioned within the chamber 1 with the tubes 7 extendin through aligned apertures or orifices in sai plates. These plates or fins are pressed together and into wedging contact with the tubes, as will later be explained, and the ends of the tubes are secured in the end plates 6 by swaging, in the manner of ordinary boiler tube construction.

In my preferred method of constructing and assembling the fins 12 upon the tubes 6 holes are punched in the lins on centers corresponding to the relative spacing of the tubes and the metal around the holes then expanded and drawn to form a circular lip 13 which converges slightly in an axial d1- rection with the wall of the lip graduall diminishing in thickness. (See Fi. 4.; This provides ns having relative a 'gned .tapered orifices 14 surrounded by laterally projecting) lips which, when the several fins are assem led together, nest into the tapered orifices of the ad]acent finsJ In assembling the tubes and fins together, the tubes are first fixed in one end plate 6 and the several fins 12 assembled on the tubes as indicated in Fi 4. Theopposite end plate is then engage over the free ends of the tubes and pressure is then applied to said end plate to compress the fins together, the lips wedging together and binding tightly against the sides of the tubes to form a rigid structure. When the ins are so compressed the lips 13 assume the shape shown in Fig. 3 and provide a maximum heat-conducting contact with the tube.

The internal diameter of the lips 13, in their initial condition (see Fig. 4:) is slightly greater than the diameter of the tubes 7 so that the plates or fins 12 will easily slip over the tubes in assembling and so that any inaccuracies in the punching of the several fins will be compensated for in the compressing together of the fins.

After the lins and the end plate are assembled and compressed on the tubes the free ends of the tubes are swaged to form a rigid structure including the two end plates, the tubes, and the fins. In assembling the other elements to this rigid tube structure the two half members of the side walls 4 are slipped between the, end plates 6 and over the tir es and fins and are then bolted together by the bolts 5. The side wall members 4 and the manifold plates 8 and 9 are then bolted to the end plates by the bolts 11.

By this structure I provide iins which wedge tightly against the walls of the tubes thus insuring' a binding metallic contact which contributes to a hi h degree of con` guctivity necessary for ecient transfer of eat.

Further by my method of construction I provide such binding of the fins on the tubes without the necessity of ati ht or close initial lit of the fins upon the tu es.

The specific embodiment illustrated in the drawings is well adapted to fulfill all the objects primarily stated but it is to be understood that I do not wish to confine my invention thereto as it is susceptible of embodiment in various other .forms all comin within the scope of the claims which follow.

I claim:

1. In a heat exchanger, a plurality of fin plates, each of said plates having a plurality of similarly spaced transverse tapered orifices and laterally projecting converging lips surrounding sald orifices, a plurality of tubes extending through valigned orifices of said iin plates and with the lips of each orifice nested into its aligned adjacent oriice, and means wedging said lips firmly be- L lips surrounding said orifices, a plurality of l tubes extending through aligned orifices of the said lin plates and with the lips of each orifice nested into its aligned adjacent ori lice, end plates joining said tubes, and means forcing said end plates together against the iin plates wedging their lips firmly between the tube walls and lips of the adjacent n plates.

3. In a heat exchanger, a tube, and a plurality of relatively spaced transverse fins, having relatively aligned orifices through which the tube extends, each fin having a circular lip surrounding the orifice and extending laterally from the plane of the iin, the diameter of the orifices at the plane of the fins being larger than the diameter of the tube and decreasing towards the end of the lips, and means for wedging the lips together and binding the same tightly against the sides of the tube.

4. In a heat exchanger, a plurality of fin plates, each of said plates having a plurality of similarly spaced transverse tapered orilices and laterally projecting converging lips surrounding said orifices, a plurality of tubes extending through aligned orifices of said iin plates and with the lips of each orifice nested into its aligned adjacent orice, and means for wedging the lips together and pressing the same tightly against the sides of the tube distorting the lips from their normal position to press or bind against the tubes.

Signed at Los Angeles, California, this 20th day of October, 1921.

EDWIN R, COX.

yWitnesses: c

CLARENCE B. FOSTER, L. BELLE WEAVER. 

